• Between 2002 and 2015, forest loss in Brazil’s southern Amazon reduced the amount of rainfall during the dry season by more than 5%, a recent study found.
• Researchers studying how deforestation in the states of Rondônia and Mato Grosso affected the atmospheric water cycle between 2002 and 2015 found that a reduction in forest cover reduced evapotranspiration and disrupted regional atmospheric systems.
• Lower rainfall during the dry season can compromise crops, boost wildfires, and reduce water supplies and river levels, sometimes leaving communities isolated.

The team from Nanjing University, China, and the University of Leeds, U.K., analyzed how deforestation in the states of Rondônia and Mato Grosso — which together are responsible for about 30% of all deforestation in the Brazilian Amazon in recent decades — affected the atmospheric water cycle between 2002 and 2015. They found that a 3.2% mean loss of forest cover led to a 5.4% reduction in dry season rainfall, highlighting that precipitation in the Amazon is highly sensitive to changes in forest cover.

[…]

“Agriculture is the major driver of deforestation in this region,” Spracklen said. “Nothing else comes close.”

Alencar said land grabbers also burn forests to signal ownership and claim territory, perpetuating an illicit cycle of clearing and land speculation.

Yet clearing forests undermines agricultural productivity. The study warns that reduced rainfall made worse by deforestation dries soils and stresses crops. Other research has predicted that continued deforestation and its impacts on rainfall could cost Brazil hundreds of billions of dollars in agricultural losses by 2050. Effectively, by destroying the Amazon, agribusiness is undermining its own viability.

[…]

Though reforestation can restore some ecological functions, Spracklen said protecting remaining primary forests takes precedence. Once the trees are burned or cleared, recovery can be slow and incomplete. “It’s a lot like triage. You’ve got to deal with the deforestation first, before you think about recovery,” he told Mongabay.

“We’ve got this very short period to get this right,” he added. “Once [the rainforest] is gone, we will look back with a lot of regret.”

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